Traveler wrote:
On 17 Aug 2005 14:27:30 -0700, "Igor" wrote:



DARTH VADER wrote:
What exactly is space time ?

A four dimensional metric space of indefinite signature.

Why cant we travell through the 4th dimention (time axis)?

We can and we do. The rotating second hand on my watch is a clear
indication of this. Time on this level seems to have a directional
arrow associated with it, but that is a thermodynamic consequence
corresponding to increasing entropy. On a fundamental level, most laws
of physics don't care which direction time goes.

Time does not change. Time is an abstract parameter used to denote
change in physics.

Only in Newtonian physics. In relativity time is a coordinate.

To describe a change in time would require a
meta-time, and a meta-meta-time for the meta-time, ad infinitum.

Wrong. All changes in spacetime in relativity are compared to
invariant proper time intervals along the worldline. Coordinate time
and proper time are two entirely different things.


Nasty Little Truth About Spacetime Physics:
http://www.rebelscience.org/Crackpots/notorious.htm

Don't let the morons in the physics community fool you, especially the
idiots, Dick van de merde and Sam Wormley. ahahaha... ahahaha...


What are you jealous that they are truly educated in this area and seem
to know what the hell they're talking about?

Igor you could do better. why not say time slows
down? But that it is not apparent to those that it has slowed down for
themselves. If your clock slows down you will see other clocks
blueshifted but your own not.

Proper time means not being able to tell any difference in your own
clock without seing others
that are not traveling through space as rapidly as
you are

Proper time is only an appearance.
The slowdown of time is an absolute.

you mean not playing the game is winning...

Lady.

In article .com
wrote:

Proper time means not being able to tell any difference in your own
clock without seing others
that are not traveling through space as rapidly as
you are

Every part of the universe is a good thing is that the only way you
can write that Down in your book in great big letters.

Proper time is only an appearance.
The slowdown of time is an absolute.

Than not believing is winning.

--
Lady Chatterly

"LMFAO, and why do you think AUK has been poking you socmans over
Chatterly so much? No other group on usenet took more than a week to
determine that LC was a bot. Now why did it take socmans over a
month? 1/4th as smart as *normal* people would be the first answer."
-- Aratzio

TERRORIST ALERT!! This moron sends your replies to alt. moron.


Dirk Van de moortel wrote:
"TomGee" wrote in message oups.com...

Dirk Van de moortel wrote:
"TomGee" wrote in message oups.com...
Worms doesn't know, that's why he sent you to a website. Spacetime is
a fictional place invented as a math construct so that we can calculate
the motion of objects through time.

According to Einsein, every object has a so-called "world line" which
indicates the object's past, current, and future position wrt its
motion through the universe.

This has nothing whatsoever to do with Einstein.


So you say.


A wordline is just a way of describing the path of an object by
giving its place as a function of time.


That's exactly what I said when I called it a math construct and not a
real place. Apparently you're having a problem with what is being
said.


Example:
{ x = 0
{ y = v0 cos(pi/3) t
{ z = v0 sin(pi/3) t - 1/2 g t^2
are the parametric equations of the wordline of a bullet, shot in the
y-direction with initial speed v0, tilted to an angle of 60 degrees
and where the acceleration due to gravity is given by g.

The start of the bullet at time t=0 is given has (x,y,z) = (0,0,0),
So in the coordinate system that we have chosen, this event in
spacetimes gets the coordinates (t,x,y,z) = (0,0,0,0).

This way the past, present and future of an idealized point-object
is described by its worldline.

The set of all possible events happening at all places and at all
possible times is called spacetime.
Since in this spacetime one needs 4 numbers to describe events,
we call it 4-dimensional.


And a set of anything is a math construct, is it not? Arithmetic, like
2+2=4. Not a real place, location, and not real, just a set of real
numbers. Does not exist adjacent nor parallel to nor out in the space
of our universe. It is a figment of the mind - a math construct.


None of this has anything to do with relativity or with Einstein.
This could be lesson 1 in every elementary physics course.


So what if it doesn't, even though that's your own opinion? Does that
make it any more real and existing somewhere other than in our minds or
as a graph or as a set of numbers?

It shows what a stupid and ignorant pig you are.
Isn't that sufficient?
http://users.pandora.be/vdmoortel/di...heOnlyWay.html
http://users.pandora.be/vdmoortel/di.../SmackDab.html
http://users.pandora.be/vdmoortel/di...bles/CRAP.html
http://users.pandora.be/vdmoortel/di...elescopic.html
http://users.pandora.be/vdmoortel/di...oRestMass.html
http://users.pandora.be/vdmoortel/di...reatMinds.html
http://users.pandora.be/vdmoortel/di...mbles/FoR.html


Pot. Kettle. Black.

In sci.physics, DARTH VADER

wrote
on 17 Aug 2005 10:07:34 -0700
.com:
What exactly is space time ?
Why cant we travell through the 4th dimention (time axis)?


Spacetime is simply the cross-product of the spatial
dimensions (of which there are three, usually expressed
in Cartesian coordinates (x,y,z)) and the time dimension,
which is measured by clocks (or attempted, given that
clocks have annoying tendencies to drift, become erratic,
and, if not regularly supplied with energy, stop).

The conventional representation of spacetime is with
four coordinates (x,y,z,t). The first three are the
aforementioned spatial coordinates, in meters; the last
is in seconds and represents time. This makes for a
rather strange metric, at least in SR; the quantity
x^2 + y^2 + z^2 - c^2t^2 is readily verified to be
invariant under the Lorentz Transformation.

Visualization of spacetime has some issues, mostly
because we can only see three dimensions. One could
visualize a hypersphere x^2+y^2+z^2+t^2 = r^2 as
an expanding, then contracting, soap bubble; that's
arguably the best one can do. Other methods include
slicing the object with a 3-space (the analogue of
a plane in regular 3-D euclidean geometry) and see
the results.

As for traveling through space-time, we do it without
any effort at all, at least in the time direction.
Seconds tick regardless of one's desires. :-) (There
are some issues regarding perception, but those are
more properly handled in neurobiological contexts,
not physics-oriented ones.)

--
#191,
It's still legal to go .sigless.

No, Ghost, we don't travel through space-time, we only travel through
space _and_ time. Biiigg difference cause s-t is a math construct and
not of this world.

"TomGee" wrote in message oups.com...
No, Ghost, we don't travel through space-time, we only travel through
space _and_ time. Biiigg difference cause s-t is a math construct and
not of this world.

Ah yes...
Measuring distances and times and using them to calculate
where and when the impact of the cannon ball will take pace
ah well, it's just "not of this world":
http://users.pandora.be/vdmoortel/di.../NotWorld.html
Brilliant point of view.

Dirk Vdm

"TomGee" wrote in message oups.com...
No, Ghost, we don't travel through space-time, we only travel through
space _and_ time. Biiigg difference cause s-t is a math construct and
not of this world.

Ah yes...
Measuring distances and times and using them to calculate
where and when the impact of the cannon ball will take place...
ah well, it's just "not of this world":
http://users.pandora.be/vdmoortel/di.../NotWorld.html
Brilliant point of view.

Dirk Vdm

well said Tom
but you have to add:
space has no curvature and no SHMERVATURE .....!!

what makes curved movement belongs to some special
unknown particle that do the curved movement!!

ATB
Y.Porat
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